Portable Tennis Racket Stringing Machine

ABSTRACT

The invention is directed toward a string clamp for a tennis racket stringing machine where the string is locked within the clamp between the end of the string clamp which is locked in place and the locking lever. This configuration allows a smaller string clamp to be utilized and also lengthens the life of the string clamp. The string clamp may have shaped feet which fit within channels in a mounting plate in a tennis racket stringing machine. The shaped feet allow the clamp to be removably secured to the mounting plate of the stringing machine when the string clamp is locked.

PRIORITY

This application is a Continuation-in-Part of U.S. application Ser. No. 14/215,537, the disclosure of which is hereby fully incorporated by reference.

FIELD OF THE INVENTION

The invention related generally to a racket stringing machine and more particularly to an improved string clamp for a tennis racket stringing machine.

BACKGROUND OF INVENTION

Tennis racquets are strung with the use of a stringing machine. Typically a stringing machine consists of three main parts: mounting plate, which holds the racquet in place, pulling mechanism, by which the strings are puller by the operator, and string clamps, which hold strings in place after they are pulled. Strings are made of many different materials and some of these materials, for example polyester or nylon, have a very low coefficient of friction. This requires the clamp to hold the string by significant force for the string not to slip.

All clamps, which hold the string, are designed with jaws, which hold the string at one of the jaw ends, while the jaws rest against each other at the other end. The locking lever is placed between these two ends. The working principle of this design is simple lever with resistance and fulcrum at the ends of the lever and the effort in the middle. This configuration always results in greater force on the clamp lever (effort) then on the string (resistance). For example to reach 300 lbs of clamping force on the string, depending on the actual clamp geometry, 400 to 600 lbs of force is needed on the clamp lever. This puts a great pressure on the clamp lever. As a result the clamp levers must be large to allow the placement of the whole hand on the lever. The lever must be also made of high quality steel, which results in high cost and weight of the clamp. Because of the high pressure the levers in stringing machine clamps break very often and must be replaced.

What is needed is a new clamp design, which would reduce the pressure on the clamp locking lever, making the clamp more reliable and also allowing a lighter clamp design for portable stringing machines.

SUMMARY OF THE INVENTION

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed innovation. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

The invention is directed toward a string clamp for a tennis racket stringing machine comprising a first end; a second end disposed distal from said first end; a first clamp member having a first end disposed at said first end of said string clamp; a second clamp member having a first end disposed at said first end of said string clamp; a locking lever configured to move said first clamp member closer to said second clamp member; a string holding portion disposed between said first clamp member and said second clamp member; wherein said string holding portion is disposed between said first end of said string clamp and said locking lever; wherein said first end of said first clamp member is configured to be secured in a fixed position relative to said first end of said second clamp member while in use.

The string clamp may further comprise one or more shaped feet disposed at said first end of said string clamp. The string clamp may further comprise wherein said first clamp member has one or more shaped feet disposed at said first end of said first clamp member and wherein said second clamp member has one or more shaped feet disposed at said first end of said second clamp member. In another embodiment of the invention, the string holding portion has a cross string recess. In another embodiment of the invention the string clamp further comprises a clamp connector disposed at said second end of said string clamp. The clamp connector may removably secured to said second end of said string clamp or the first end of said string clamp. In another embodiment of the invention, the string clamp further comprises a securing member disposed between said first clamp member and said second clamp member.

The string clamp may also comprise a first end; a second end disposed distal from said first end; a first clamp member having one or more shaped feet disposed at a first end; a second clamp member having one or more shaped feet disposed at a first end; a string holding portion, wherein said string holding portion is disposed between said first clamp member and said second clamp member; a locking lever connecting said first clamp member and said second clamp member; wherein said string holding portion is disposed between said first end of said first clamp member and said first end of said second clamp member and said locking lever; wherein said first end of said first clamp member is configured to be secured in a fixed position relative to said first end of said second clamp member while in use.

The invention is also directed toward a method for locking tennis racket strings in place. The method comprises placing a string clamp over a string bed; placing a string between said first clamp member and said second clamp member; positioning said string in said string holding portion; fixing said first end of said first clamp member in a fixed position relative to said first end of said second clamp member; and engaging said locking lever to lock said string in a fixed position between said first clamp member and said second clamp member.

The method may further comprise placing a securing member between said first clamp member and said second clamp member. The method may further comprise respectively placing said one or more shaped feet within one or more channels disposed in a mounting plate disposed on a tennis racket stringing machine; and respectively securing said one or more shaped feet within said one or more channels such that said string clamp is immovably secured to said mounting plate when said locking lever is disposed in a locked position.

Still other embodiments of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described the embodiments of this invention, simply by way of illustration of the best modes suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modifications in various obvious aspects all without departing from the scope of the invention. Accordingly, the drawing and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of this invention will be described in detail, wherein like reference numerals refer to identical or similar components, with reference to the following figures, wherein:

FIG. 1 is a side view of the preferred embodiment of the string clamp;

FIG. 2 is a front view of the preferred embodiment of the string clamp; and

FIG. 3 is a side view of an alternative embodiment of the string clamp.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The claimed subject matter is now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident, however, that the claimed subject matter may be practiced with or without any combination of these specific details, without departing from the spirit and scope of this invention and the claims.

Referring to FIG. 1 and FIG. 2, the preferred embodiment of the string clamp 100 is illustrated. In the preferred embodiment the string clamp 100 comprises a front clamp member 102, a rear clamp member 104, and a locking lever 106 connecting the front clamp member 102 to the rear clamp member 104.

Clamped between the front clamp member 102 and the rear clamp member 104 is a string 200. The string clamp 100 thus holds the string 200 in a stable position during the stringing process. The string clamp 100 has one or more shaped feet 110. In the preferred embodiment the shaped feet 110 are placed into channels in a mounting base on a stringing machine (not shown). The channels allow the shaped feet 110 to be securely locked into position on the mounting plate.

The string clamp 100 has string holding portion 112. The string holding portion 112 is the area of the string clamp 100 which directly contacts and holds the string 200. The string holding portion 112 has a cross string recess 114. The cross string recess 114 is a recess into a portion of the string holding portion 112 which allows a string 200 which has already been tightened and is at a ninety degree angle to the string 200 being held within the string holding portion 112 between the front clamp member 102 and the rear clamp member 104.

In the preferred embodiment of the string clamp 100, the shaped feet 110 of the string clamp 100 are locked in place by the channels in the mounting plate so that the shaped feet 110 end of the string clamp 100 are in a fixed relative position and the bottom end of the front clamp member 102 and the bottom end of the rear clamp member 104 are immovable. This creates a fulcrum at the bottom end of the string clamp 100. The locking lever 106 is positioned at a distal end of the string clamp 100 with the string holding portion 112 disposed between the fulcrum and the locking lever 106. This configuration is an improvement over prior art string clamps where the string holding portion is disposed at the distal end of the string clamp. In the prior art configuration a greater amount of force is needed at the locking lever since the locking lever is disposed between the fulcrum and the string holding portion. In the current invention the string holding portion 112 is disposed between the fulcrum and the locking lever 106, allowing for less force to be used in the locking lever 106 to hold the string 200 secure within the string holding portion 112.

By engaging the locking lever 106, the string clamp 100 locks the string 200 at the same time as the string clamp 100 locks in place to the mounting plate. The force of the locking lever 106 forces the shaped feet 110 end of the string clamp 100 apart, securing the shaped feet 110 into the channels of the mounting plate.

In another embodiment of the invention the string clamp 100 may utilize a removable connector plate (not shown) at the top end of the string clamp 100 to hold the front clamp member 102 against the rear clamp member 104 instead of a locking lever 106 or in addition to the locking lever 106. This configuration allows for smaller force on the locking lever 106 then on the string being held, as the string clamping force is divided between the connector plate and the locking lever 106. As only small force on the lever is required, the locking lever can be much smaller and lighter, while the reliability is greatly improved. In another embodiment, the string clamp 100 may also be height adjustable, allowing the string clamp 100 to be positioned in place and the heightened up to the level of the string bed.

Referring to FIG. 3, an alternative embodiment of the invention is illustrated. FIG. 3 illustrates a floating string clamp which does not connect to a mounting plate of a stringing machine but instead connects to a string 200 which has already been secured to a racket. In the alternative embodiment the string clamp 150 has a front clamp member 152 and a rear clamp member 154 connected by a clamp connector 156. Disposed between the front clamp member 152 and the rear clamp member 154 is a securing member 160. The locking lever 106 connects the front clamp member 152 and rear clamp member 154 to the securing member 160. In other embodiment the securing member 160 is an independent item and is unconnected to the string clamp 150. In this embodiment the clamp connector 156 operates as the fulcrum. The string 200 is disposed between the securing member 160 and the front clamp member 152 and the rear clamp member 154. The portion of the string 200 which had already been secured may be place adjacent to the front clamp member 152 or the rear clamp member 154. The portion where the string 200 is held by the securing member 160 and the clamp 150 is the string holding portion 112. The string clamp 150 and the securing member 160 may have a cross string recess.

In another embodiment the string clamp 150 is placed over the strings 200 so that the securing member 160 is disposed between the two strings 200. Then a connector member 156, which is a separate component from the string clamp 150 is placed over the upper ends of the front clamp member 152 and rear clamp member 154. Finally the user places the locking lever 106 at the other end of the string clamp 150 and engages the locking lever 106.

To use the preferred embodiment of the string clamp the user places the string clamp 100 over the string 200 from above, placing the string 200 in the string holding portion 112 of the string clamp 100. The user places the shaped feet 110 within the channels of the mounting plate. The user then ensures that the shaped feet 110 are secure within the channels of the mounting plate and cannot move. The user then engages the locking lever 106, fully securing the string 200 within the string holding portion 112 of the string clamp 100. Once the user has fully secured the string 200 to the racket the user disengages the locking lever 106, removes the string clamp 100 from the string bed, and places the string clamp 100 in its next position, repeating the process.

If the user utilizes the floating string clamp 150 then the user places the string clamp 150 over the strings 200, placing one string 200 between the securing member 160 and the front clamp member 152 and another string 200 between the securing member 160 and the rear clamp member 154. If the securing member is separate and distinct from the floating string clamp 150 then the user places the securing member 160 between the strings 200. The user may then engage the locking lever 106 to lock the strings 200 in place within the floating string clamp 150. Once the user has fully secured the string 200 to the racket the user disengages the locking lever 106, removes the string clamp 150 from the string bed, and places the string clamp 150 in its next position, repeating the process.

The inventive design of the string clamp 100 creates unforeseen benefits over the prior art. By having the string holding portion 112 disposed between the fulcrum point of the string clamp (either the shaped feet 110 or the clamp connector 156) and the locking lever 106, the string clamp 100 can be designed so that a smaller string clamp 100 may be utilized to generate the same amount of force as a larger string clamp 100 in the standard configuration where the string holding portion 112 is at the distal end of the string clamp 100. It also allows the string clamp 100 to be utilized longer without breaking since users tend to overtighten stand string clamps.

In other embodiments the mounting plate having channels may be the same part of the stringing machine as the mounting plate which holds the racket or may be a separate component of the stringing machine.

What has been described above includes examples of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art can recognize that many further combinations and permutations of such matter are possible. Accordingly, the claimed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.

The foregoing method descriptions and the process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by one of skill in the art the order of steps in the foregoing embodiments may be performed in any order. Words such as “thereafter,” “then,” “next,” etc. are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the methods. Further, any reference to claim elements in the singular, for example, using the articles “a,” “an” or “the” is not to be construed as limiting the element to the singular.

The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein. 

1) A string clamp for a tennis racket stringing machine comprising a) a first end; b) a second end disposed distal from said first end; c) a first clamp member having a first end disposed at said first end of said string clamp; d) a second clamp member having a first end disposed at said first end of said string clamp; e) a locking lever configured to move said first clamp member closer to said second clamp member; f) a string holding portion disposed between said first clamp member and said second clamp member; g) wherein said string holding portion is disposed between said first end of said string clamp and said locking lever; h) wherein said first end of said first clamp member is configured to be secured in a fixed position relative to said first end of said second clamp member while in use. 2) The string clamp as in claim 1 further comprising one or more shaped feet disposed at said first end of said string clamp. 3) The string clamp as in claim 2 wherein said first clamp member has one or more shaped feet disposed at said first end of said first clamp member and wherein said second clamp member has one or more shaped feet disposed at said first end of said second clamp member. 4) The string clamp as in claim 1 wherein said string holding portion has a cross string recess. 5) The string clamp as in claim 1 further comprising a clamp connector disposed at said second end of said string clamp. 6) The string clamp as in claim 5 wherein said clamp connector is removably secured to said second end of said string clamp. 7) The string clamp as in claim 1 further comprising a clamp connector disposed at said first end of said string clamp. 8) The string clamp as in claim 8 wherein said clamp connector is removably secured to said first end of said string clamp. 9) The string clamp as in claim 3 wherein said string holding portion has a cross string recess. 10) The string clamp as in claim 1 further comprising a securing member disposed between said first clamp member and said second clamp member. 11) The string clamp as in claim 10 wherein said string holding portion has a cross string recess. 12) A string clamp for a tennis racket stringing machine comprising a) a first end; b) a second end disposed distal from said first end; c) a first clamp member having one or more shaped feet disposed at a first end; d) a second clamp member having one or more shaped feet disposed at a first end; e) a string holding portion, wherein said string holding portion is disposed between said first clamp member and said second clamp member; f) a locking lever connecting said first clamp member and said second clamp member; g) wherein said string holding portion is disposed between said first end of said first clamp member and said first end of said second clamp member and said locking lever; h) wherein said first end of said first clamp member is configured to be secured in a fixed position relative to said first end of said second clamp member while in use. 13) The string clamp as in claim 12 wherein said string holding portion has a cross string recess. 14) The string clamp as in claim 12 further comprising a clamp connector disposed at said second end of said string clamp. 15) The string clamp as in claim 14 wherein said clamp connector is removably secured to said second end of said string clamp. 16) The string clamp as in claim 12 further comprising a securing member disposed between said first clamp member and said second clamp member. 17) The string clamp as in claim 16 wherein said string holding portion has a cross string recess. 18) A method for locking tennis racket strings in place comprising a) placing a string clamp over a string bed, wherein said string clamp comprises i) a first end; ii) a second end disposed distal from said first end; iii) a first clamp member having a first end disposed at said first end of said string clamp; iv) a second clamp member having a first end disposed at said first end of said string clamp; v) a locking lever configured to move said first clamp member closer to said second clamp member; vi) a string holding portion disposed between said first clamp member and said second clamp member; vii) wherein said string holding portion is disposed between said first end of said string clamp and said locking lever; viii) wherein said first end of said first clamp member is configured to be secured in a fixed position relative to said first end of said second clamp member while in use; b) placing a string between said first clamp member and said second clamp member; c) positioning said string in said string holding portion; d) fixing said first end of said first clamp member in a fixed position relative to said first end of said second clamp member; e) engaging said locking lever to lock said string in a fixed position between said first clamp member and said second clamp member. 19) The method as in claim 18 further comprising placing a securing member between said first clamp member and said second clamp member. 20) The method as in claim 18 wherein said string clamp has one or more shaped feet disposed at said first end of said clamp and wherein said method further comprises a) respectively placing said one or more shaped feet within one or more channels disposed in a mounting plate disposed on a tennis racket stringing machine; b) respectively securing said one or more shaped feet within said one or more channels such that said string clamp is immovably secured to said mounting plate when said locking lever is disposed in a locked position. 